Clinical and radiological evaluation including transcranial Doppler of vertebral arteries of patients with vertebrobasilar insufficiency attending assiut university hospital and assessment of possible risk factors that may lead to vertebrobasilar insufficiency.

Vertebrobasilar insufficiency (VBI) is defined by inadequate blood flow through the posterior circulation of the brain, supplied by the 2 vertebral arteries that merge to form the basilar artery. Transient ischemic attacks in the vertebrobasilar system represent 20% of all transient ischemic attacks, Their diagnosis is more difficult than that of ischemic attacks in the anterior circulation because its manifestations are subjective and difficult to quantify. Although traditionally VB stroke is regarded as having a more benign outcome when compared to anterior circulation stroke, data is still conflicting, with some studies showing a higher impairment in VB stroke patients with 21% of death or major disability at 3 months. Transient ischemic attacks and, more rarely, infarcts in the posterior circulation may be due to subclavian steal syndrome. Basilar artery transient ischemic attacks usually occur after the six decade, syncopal attacks occur in about 10% sudden in onset and brief in duration. Regarding the clinical presentation of VB stroke, the common symptoms are dizziness, unilateral limb weakness, headache, vomiting and nausea; as for clinical signs, the most frequent are unilateral limb weakness, gait ataxia, unilateral limb ataxia, dysarthria and nystagmus. Previously, there was no simple and effective method for the detection of VBI, but in recent years, with the development and progress of medical technology and the emergence of Transcranial Doppler (TCD), it provides an accurate, noninvasive, and simple method for the diagnosis of VBI. Through the diagnosis results, it will be clear about the blood flow status of single vessel and vascular compliance, which is helpful for accurate reflection of the subtle changes of VBI.

Inclusion Criteria:

1. patients with vertigo of central origin, syncopal attacks, frequent imbalance that not related to aural origin.
2. clinical examination and imaging (MRI or CT) with the diagnosis standard of vertebrobasilar insufficiency including vertebrobasilar stroke and vertebrobasilar TIA.
3. patients with abnormal lipogram and cervical spondylosis
4. patients aged > 45 years old of both sex.

Exclusion Criteria:

1. subjective complain of aural vertigo or test to exclude aural vertigo.
2. patients with malignant tumor.
3. pregnant or lactating women.
4. cognitive impairment and mental illness.